ECG Patterns in Acute Myocardial Ischemia & Infarction ISCE Conference, 2009 Panama City, FL UCSF Current of Injury in Infarction Ecgsim.exe Adrian Van Oosterom & Thom Oostendorp ICE, Cologne, 2006 Cellular basis for ST segment elevation (injury current) Isoelectric Line Holland & Arnsdorf Prog Cardiovasc Dis 1977;19:431-7; Janse MJ. Can J Cardiol 1986;A46-A52. V2 Patient admitted with unstable angina who developed acute MI while having continuous ST-segment monitoring V3 5:37 Baseline 5:42 5:48 5:52 V4 ST Segment Deviation Direction: Epicardial vs Endocardial Ischemia +5 +5 - 15 From: Holland & Arnsdorf Prog Cardiovasc Dis 1977;19:431-457 Prevalence of Acute MI Location n = 41,021 Inferior 58% 97% Anterior 39% Other 3% Newby et al, GUSTO Study J Am Coll Cardiol 1996;27:625-32. Prevalence of Culprit Artery n = 22,701 with cardiac cath data RCA 45% 57% LCX 12% LAD 36% Newby et al, GUSTO Study J Am Coll Cardiol 1996;27:625-32. Right Coronary Artery (RCA) Occlusion Inferior Leads _ _ _ + III + aVF + II Acute Inferior Wall MI If occlusion is proximal to the RV branch, concommitent RV infarction UCSF ECG clue to RV infarction is ST↑ in Lead V1 LV RV RV Le ad s V1 UCSF Initial ECG Acute inferior wall MI UCSF RV Leads are the “mirror image” of standard precordial leads V2R V1R V1 V2 V4R Standard Precordial Leads RV Leads UCSF 2nd ECG is recorded with RV leads Standard Precordial Leads Right Ventricular Leads V2R V1R V3R V4R V5R V6R UCSF Anterior Leads LV RV V2 V3 V4 Acute Anterior Wall MI V1-V3 Posterior Inferior II, III, aVF Left Circumflex Artery (LCX) Occlusion From: Wagner, GS. Marriott’s Practical Electrocardiography (9th ed.) 1994;143. Posterior ECG Leads Effect of distance between electrode & ischemic zone Baseline V9 PCI Balloon Inflation LCX Artery V8 V7 Air LV RV Salt water V1 V2 V3 UCSF 47 y/o Male Presenting to the ED With Chest Pain Normal Normal Normal Normal ECG Recorded in CCU After VT/VF Arrest Endocardial current of injury aVR aVL I Precordial Leads III aVF II Isolated T wave inversion as an early sign of acute MI Wellens' sign of impending anterior MI Hospital admission (Sx unstable angina) Hospital Day 2 (episode chest pain) Hospital Day 3 (acute anterior MI) Symmetrical T wave inversions in leads V2-3 with sharply negative T downstroke at an angle of 60º - 90º is predictive of proximal LAD disease de Zwaan, Bar, & Wellens. Am Heart J 1982;103:730. ECG Patterns in Acute Myocardial Ischemia & Infarction Thank You ISCE Conference, 2009 Panama City, FL UCSF